Improvement in wrenches



L. S. STARRETT. Wrench.

No. 212,760. Patented Feb. 25, 1879-.

ATTORNEY yWITNESSES w UNITED; STATES PATENT @QFFIGE.

LAROY S. STARBETT, ()F ATHOL, MASSACHUSETTS.

IMPROVEMENT IN WRENCHES.

Specification forming part of Letters Patent N o. 2 l 2, dated February 25, 1879; application filed September 22, 1877.

To all whom it may concern:

Be it known that I, LAROY S. STARRETT, of Athol, in the county of Worcester and State of Massachusetts, have invented a new and valuable Improvement in Wrenches and I do hereby declare that the following is a full, clear, and exact description of the construction and operation of the same, reference being had to the annexed drawings, making a part of this specification, and to the letters and figures of reference marked thereon.

Figure 1 of the drawings is a representation of a longitudinal central section ofmy improved wrench. Fig. 2 is a side view thereof. Figs. 3 and 4 are details, and Fig. 5 is a cross-section of the same.

This invention relates to improvements upon the wrench for which I was granted Letters Patent, dated May 8, 1877, and numbered 190,636; and consists, first, in the substitution for the long working-screw shown in said patent of a short working-screw playing in a longitudinal recess, which occupies about half of the length of the frontedge of the jaw-bar, and is of sufiicient depth to afford in its front end wall a bearin g for the journal of said short screw; and, second, in the construction of the jawbar and stationary jaw with recesses for the purpose of rendering them more perfectly annealable when a cast bar is used.

In the drawings, the letter A designates the end or stationary jaw of the wrench, from which extends a strong jaw-bar, B, which is provided with a tang, G, for insertion into the handle D, to which it is designed to be rigidly secured. In the front edge of the jawbar B is sunk a longitudinal recess, 1), deep enough to allow the short working-screw E to be sunk therein about half the diameter of said screw, which is provided with a milled head or rose, k, which is sunk in a transverse recess, h, deeper than the longitudinal recess. The rose 70 is about twice the diameter of the screw, and its sunken portion abuts against the rear wall of the transverse recess h, which rear wall thus resists the entire strain exerted against the movable jaw and screw, the journal at playing sufficiently in the recess m to permit of such abutment when the strain is brought upon the movable jaw. The rose is is provided with a journal, a, playing in a removable journal box or hearing, m, located at the rear of the transverse recess h, and this journal box or bearing an is provided with'au arm or tang, m, which extends into the handle D, and said bearing is thereby held in place.

v The upper end of the screw is provided with a pin, 19, secured in the shoulder a of the 1011- gitudinal recess 6.

In putting these parts together, the sliding jaw and brace are first placed upon the jawbar, and the working-screw is then fitted in the inner recess, b, its forward end resting upon the pin provided for it in the front wall of the recess 1). The journal of the operating rose or milled head is is then inserted into its journal-box and said box placed upon its seat, with its tang or arm extending along the tang of the jaw-bar, upon which the handle D is placed.

F designates the movable jaw, designed to slide on the jaw-bar and working-screw. It is provided with an extension or neck, G, which surrounds the jaw-bar and screw, and is of suflicient length to brace the jaw to its work when set. In this jaw F, on its under side, a recess or chamber, K, is formed to receive the head r of the brace L, which is pivoted therein, and provided above its pivot with a seat for a spring, it, one end of which is secured thereto, and the other bears against the recess K in the jaw F.

At the other end, 2, of this braceL is a loop, c, which extends around the jaw-bar, and 011 the inner surface of the end z of the brace is a screw-thread, which gives said end 2 the character of a half-nut, which is designed to engage with the Working-screw when brought up against the same. The loop 2; is large enough to allow this half-nut to be swung free or disengaged from the screw when desired. Otherwise, said half-nut will be kept to its engagement with the screw by the action of the spring above referred to.

When the half-nut of the brace is disengaged the movable jaw may be rapidly adjusted by sliding it along the jaw-bar. For fine adjustment the half nut is brought into engagement with the screw E, which is turned by means of its milled head or rose k. In order to disengage the brace from the screw pressure is exerted upon the top of the loop 4; or thumb-piece.

Through the entire length of the back edge of the jaw-bar B extends a groove, y, which is about half as deep as said bar is wide, and in thefront face of the stationary jaw A is a recess, w. The object of this groove and recess is to reduce the bulk of the parts in which they are located, and permit said parts to be thoroughly annealed when a cheap cast bar and jaw are used, while at the same time the working-faces and strength of said parts are not impaired.

I claim as my invention 7 1. In a wrench, the combination, with a recess, b, in the front of the bar, and the short screw E, having a milled head, 75, of the jaw F, provided with a recess, K, for the reception of the end of the half-nut brace L, which is pivoted in said recess, substantially as specified.

2. In combination with the stationary jaw A of the wrench-stock B, having the recess 1) and short screw E, the movable jaw F and brace L, pivoted in a recess, K, in said jaw, and the spring t, seated in the brace and bearing against the recess K, substantially as specified.

In testimony that I claim the above I have hereunto subscribed my name in the presence of two witnesses.

LAROY S. STARRETT.

Witnesses:

CHARLES W. BANNON, HENRY H. EARLE. 

